萌新初学Tarjan LCA，这个代码90分，WA了一个点

#include <bits/stdc++.h>
using namespace std;
vector<int> tree[500001],qus[500001];
int f[500001],diff[500001],vis[500001],fa[500001];
inline int find(int x)
{
	if(x==f[x]) return x;
	f[x]=find(f[x]);
	return f[x];
}
inline void merge(int x,int y)
{
	int t1=find(x);
	int t2=find(y);
	if(t1!=t2) f[t2]=t1;
}
inline void LCA(int u)
{
	vis[u]=1;
	for(int i=0;i<tree[u].size();i++)
	{
		int v=tree[u][i];
		if(!vis[v])
		{
			fa[v]=u;
			LCA(v);
			merge(u,v);
		}
	}
	for(int i=0;i<qus[u].size();i++)
	{
		if(vis[qus[u][i]]==2)
		{
			diff[u]++;
			diff[qus[u][i]]++;
			int fx=find(qus[u][i]);
			diff[fx]--;
			diff[fa[fx]]--;
		}
	}
	vis[u]=2;
}
inline void dfs(int u)
{
	vis[u]=1;
	for(int i=0;i<tree[u].size();i++)
	{
		if(!vis[tree[u][i]]) 
		{
			dfs(tree[u][i]);
			diff[u]+=diff[tree[u][i]];
		}
	}
}
int main()
{
	int n,tmp1,tmp2;
	scanf("%d",&n);
	scanf("%d",&tmp1);
	int ans=tmp1;
	for(int i=2;i<=n;i++) 
	{
		scanf("%d",&tmp2);
		qus[tmp2].push_back(tmp1);
		qus[tmp1].push_back(tmp2);
		tmp1=tmp2;
	}
	for(int i=1;i<n;i++) 
	{
		scanf("%d %d",&tmp1,&tmp2);
		tree[tmp1].push_back(tmp2);
		tree[tmp2].push_back(tmp1);
		f[i]=i;
	}
	LCA(1);
	memset(vis,0,sizeof(vis));
	dfs(1);
	for(int i=1;i<=n;i++) if(i!=ans) diff[i]--;
	for(int i=1;i<=n;i++) printf("%d\n",diff[i]);
	return 0;
}

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